Adding the focalboard plugin feature flag (#17682)

model/feature_flags.go

@@ -31,6 +31,7 @@ type FeatureFlags struct {
 	// Feature flags to control plugin versions
 	PluginIncidentManagement string `plugin_id:"com.mattermost.plugin-incident-management"`
 	PluginApps               string `plugin_id:"com.mattermost.apps"`
+	PluginFocalboard         string `plugin_id:"focalboard"`
 
 	// Control support for custom data retention policies
 	CustomDataRetentionEnabled bool
@@ -46,6 +47,7 @@ func (f *FeatureFlags) SetDefaults() {
 
 	f.PluginIncidentManagement = "1.9.3"
 	f.PluginApps = ""
+	f.PluginFocalboard = ""
 	f.CustomDataRetentionEnabled = false
 }